JP2019093534A - Wire electric discharge machining device - Google Patents

Abstract

To shorten automatic connection time in a conveyance device.SOLUTION: A wire electric discharge machining device includes a travel device 1. A conveyance device 13 of the travel device 1 includes: a jet nozzle 13A; an aspirator 13B; and a jet nozzle 13C. The jet nozzle 13A is provided between a direction conversion pulley 10 and a winding roller 14A on a tip side of a lower arm 5. The jet nozzle 13A delivers a wire electrode WE in the direction of the winding roller 14A with high-pressure jet while guiding the wire electrode WE with only restraint force of the high-pressure jet by jetting the high pressure jet in the direction of the winding roller 14A. The aspirator 13B is provided on an outlet side of the winding roller 14a. The aspirator 13B sucks and captures a tip of the wire electrode WE delivered by the high-pressure jet.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a wire electric discharge machining device provided with a conveying device for feeding a wire electrode to a take-up roller during automatic wire connection.

  A general-purpose wire electric discharge machining apparatus is configured such that a wire electrode is drawn from a wire bobbin to go around a tension roller, and wound around a winding roller through an upper wire guide and a lower wire guide. Since the wire electrode wears out the surface due to the discharge, it is stretched with a predetermined tension between the upper and lower wire guides during machining so that the unused surface is always located in the machining gap. I am traveling at speed.

  There is known a wire electric discharge machining device provided with an automatic wire connection device for automatically stretching wire electrodes between upper and lower wire guides. The automatic wire connection device feeds the wire electrode toward the upper wire guide by the feed roller, sequentially inserts it through the upper and lower wire guides, guides the wire electrode to the outside of the processing tank by the transfer device provided in the lower arm, and Capture on winding roller. There are mainly a belt conveyor method and an actuator method as a method of conveying the wire electrode in the conveying device.

  Patent Document 1 discloses a wire electric discharge machining device provided with a typical belt conveyor type conveying device. The conveyor device of the belt conveyor type is advantageous for the transportation of a relatively large wire electrode having a diameter of 0.2 mm or more, since the pair of endless belts directly sandwiches the wire electrode and moves the wire electrode. However, the belt conveyor enlarges the entire apparatus. Also, when transporting a wire electrode having a relatively small diameter, particularly a wire electrode having a diameter of less than 0.1 mmφ, which is referred to as an ultrafine wire, the load given to the wire electrode is large, and the wire electrode is broken, wound, or derailed. To reduce the success rate of automatic connection.

  Patent document 2 or patent document 3 discloses a wire electric discharge machining device provided with a typical actuator type conveying device. The actuator type transport device fills the guide pipe with high-pressure water flow and sucks it along with the wire electrode, delivers it by the delivery roller while guiding the wire electrode, and transports the wire electrode. Excellent. However, for wire electrodes that are high in rigidity and easy to be wrinkled, especially for large diameter wire electrodes, the restraining force due to high-pressure water flow is apt to be insufficient, and it is easy to catch and buckle in thin guide pipes. Absent.

Unexamined-Japanese-Patent No. 1-140924 Unexamined-Japanese-Patent No. 1-135426 JP-A 5-92322

  Over the years, the time required for automatic wiring has been reduced, but at least the reduction in time in the transport system has reached about the limit. Also, in the case of the belt conveyor system, the endless belt is worn out, and in the case of the actuator system, the guide pipe is worn away to roughen the inner surface or dust containing wire electrode powder is accumulated in the guide pipe. The clogging reduces the transport capacity in a relatively short time. Once the wire electrode has failed to be transported, the wire electrode can not be easily removed from the transport device, and it takes time and effort for recovery work.

  In view of the above problems, the present invention has as its main object to provide a wire electric discharge machining device provided with a novel conveyance device capable of further shortening the conveyance time. Some of the advantages that can be obtained by the wire electrical discharge machining device of the present invention will be illustrated in each case in the description of the specific embodiments.

  In view of the above problems, the wire electric discharge machining apparatus of the present invention is fixed to a mechanical structure, for example, a column (6) outside the processing tank (4), and the tip is positioned inside the processing tank (4). A redirecting pulley (10) provided directly below the lower wire guide unit (3B), provided with a lower arm (5) for supporting the lower wire guide unit (3B) provided at the tip and guiding the wire electrode (WE) And a take-up roller (13A) provided on the outside of the processing tank (4), the direction changing pulley (10) and the take-up roller (14A) at the tip end side of the lower arm (5) And jet the high-pressure jet toward the winding direction of the take-up roller (14A) while guiding the wire electrode (WE) only by the restraining force of the high-pressure jet. A jet nozzle (13A) that feeds and flies in the direction of the take-up roller (14A) and a tip of a wire electrode (WE) provided on the outlet side of the take-up roller (14A) and sent by high pressure jet And an aspirator (13B) for capturing.

  The wire electric discharge machining apparatus of the present invention desirably covers the high pressure jet and the wire electrode (WE) fed by the high pressure jet in at least the processing tank (4) between the jet nozzle (13A) and the aspirator (13B). Make it cover (7).

  The reference numerals in the parentheses correspond to the reference numerals in the drawings, but are provided for the convenience of description in understanding the present invention, and the present invention is limited to the specific embodiments shown in the drawings. Absent.

  According to the present invention, since the wire electrode is put on the high pressure jet and blown to move from the front end to the rear end of the lower arm at a stretch, the transfer time can be considerably shortened. Further, since the endless belt or the guide pipe is not provided, the conveying device is not easily deteriorated, and the conveying ability can be maintained for a long time. Then, even if the wire electrode fails to be transported, there is no obstacle between the jet nozzle and the aspirator, so the wire electrode can be easily removed, and the recovery operation is easy. As a result, the time required for the automatic connection can be shortened without reducing the success rate of the automatic connection, and the work efficiency is improved.

It is a figure showing typically the composition of the whole wire electric discharge machining device of the present invention. It is a figure which shows typically the conveying apparatus of the wire electric discharge machining apparatus of this invention.

  FIG. 1 shows the whole outline of the wire electric discharge machining device of the present invention. FIG. 1 shows the supply side of the wire electrode as viewed from the front of the main machine, and the recovery side of the wire electrode as viewed from the left side of the main machine, in order to show the entire traveling path of the wire electrode on one side. It shows in the state. Further, in FIG. 1, in order to make the plurality of constituent members easy to understand, it should be noted that the relative sizes and positional relationships of the plurality of constituent members are different from the actual one.

  First, the entire configuration of the wire electric discharge machining apparatus according to the embodiment shown in FIG. 1 will be described. The wire electric discharge machining device according to the embodiment includes at least a traveling device 1, an automatic wire connection device 2, a wire guide unit 3, a control device (not shown), a power supply device, and a relative movement device. A portion where the traveling device 1, the automatic connection device 2, the wire guide unit 3, and the relative movement device are provided is referred to as a main machine.

  The traveling device 1 supplies the unused wire electrode WE to the processing gap GP formed between the wire electrode WE and the workpiece WP, and recovers the used wire electrode WE subjected to the processing. Means to The traveling device 1 includes a supply device 11, a tension device 12, a transport device 13, and a recovery device 14. From the feeding device 11 to the tensioning device 12 and the upper wire guide 3A via the automatic connection device 2 to be the feeding side 1A of the wire electrode WE, from the lower wire guide 3B to the recovery device 14 via the conveying device 13 To the collection side 1B of the wire electrode WE.

  The automatic connection device 2 is means for automatically stretching the wire electrode WE. The automatic connection device 2 of the wire electric discharge machining device according to the embodiment includes a delivery roller 2A, a guide pipe 2B, and a cutter 2C. The delivery roller 2A is means for delivering the wire electrode WE by being rotated by the delivery motor 2M. The guide pipe 2B is a means for guiding the tip of the wire electrode WE to the upper wire guide unit 3A. The cutter 2C is a means for cutting the wire electrode WE. For example, the cutter 2C can be replaced with other means for cutting the wire electrode WE, such as a heating roller for cutting the wire electrode.

  The wire guide unit 3 includes an upper wire guide unit 3A and a lower wire guide unit 3B. The upper and lower wire guide units 3A and 3B respectively process the wire guide 30A (guide main body) for positioning and guiding the wire electrode WE, the conducting body 30B for supplying power to the wire electrode WE, and the processing fluid supplying the working fluid jet to the processing gap GP. It is an assembly formed integrally with the liquid jet nozzle 30C.

  The control device, which is not shown, is means for controlling the operation of the wire electric discharge machining device. The control device and the traveling device 1, the automatic connection device 2, the processing power supply device, or the relative movement device are each connected by one or more signal lines, and execute a predetermined sequence operation. The control device causes the traveling device 1, the automatic connection device 2, the processing power supply device, and the relative movement device to execute specific operations according to the NC program, and arbitrarily controls the overall operation of the wire electric discharge machining device It includes a numerical controller that performs the desired processing.

  The machining power supply is a means for continuously supplying a discharge current pulse having a desired waveform and a peak current value to the machining gap GP. The relative movement device is means for relatively moving the wire electrode WE and the workpiece WP in two horizontal axis directions. The relative movement device includes a taper device that tilts the wire electrode WE and the workpiece WP.

  The processing tank 4 is a means for containing the workpiece WP. Moreover, the processing tank 4 is a means to accommodate a processing liquid. When processing is performed by the “flushing method” in which the processing fluid jet is jetted and supplied to the processing gap GP in a state where the workpiece WP is exposed to air, the tank wall prevents the processing fluid from being scattered and the processing tank 4 Act as a splash guard. When processing is performed according to the “die sinking method” in which the workpiece WP is immersed in the processing liquid, the tank wall prevents the leakage of the processing liquid, and the processing tank 4 literally functions as a tank.

  The lower arm 5 is a means for supporting the lower wire guide unit 3B. In the wire electric discharge machining apparatus according to the embodiment, the lower arm 5 is provided obliquely to the front side of the main machine so that the tip can be arranged in the machining tank 4 beyond the tank wall of the machining tank 4. ing. The lower arm 5 can be provided horizontally through the tank wall of the processing tank 4. However, installing the lower arm 5 obliquely is advantageous in that it is not necessary to provide a seal between the tank wall of the processing tank 4 and the lower arm 5.

  The rear end of the lower arm 5 is fixed to the machine structure outside the processing tank 4. Specifically, in the wire electric discharge machining device according to the embodiment, the lower arm 5 is fixed to the column 6 together with the recovery unit to which the winding roller 14A of the recovery device 14 is attached. The tip of the lower arm 5 is provided so as to be located inside the processing tank 4. The lower arm 5 supports the lower wire guide unit 3B and the direction changing pulley 10 at its tip.

  The direction changing pulley 10 is rotatably attached immediately below the lower wire guide unit 3B in the guide block 20 fixedly provided at the tip of the lower arm 5. The direction changing pulley 10 changes the traveling direction of the wire electrode WE traveling in the vertical direction with respect to the installation surface of the workpiece WP substantially at right angles to the direction of the winding roller 14A which is approximately horizontal.

  Next, the traveling device 1 of the embodiment will be described more specifically. The supply device 11 of the traveling device 1 is a means for supplying the wire electrode WE to the processing gap GP. The supply device 11 includes a reel 11A, a wire bobbin 11B, a servo pulley 11F, and a brake 11M. However, the wire bobbin 11B is a replaceable consumable that is stored by winding a wire electrode WE having a predetermined length around an axis. The wire bobbin 11B is loaded into the reel 11A and rotates.

  The reel 11A rotates in accordance with the speed at which the tension device 12 continuously draws the wire electrode WE from the wire bobbin 11B. The brake 11M is, for example, a torque motor or a powder clutch. The brake 11M is provided directly connected to the rotation shaft of the reel 11A, and prevents the wire bobbin 11B from idling by applying a load in a range in which the reel 11A can rotate in the opposite direction to the rotation direction of the reel 11A. The servo pulley 11F moves up and down according to the fluctuation of the tension of the wire electrode WE by its own weight, and absorbs the vibration of the traveling wire electrode WE supplied from the wire bobbin 11B.

  The tension device 12 is a means for feeding out the wire electrode WE from the wire bobbin 11 and sequentially delivering it to the processing gap GP. The tension device 12 is a means for applying a predetermined tension to the wire electrode WE supplied to the processing gap GP with the rotating device 14. The tension device 12 includes a drive roller 12A, a driven roller 12B, a pinch roller 12C, and a servomotor 12M. The strain gauge 12T is a tension detector. The limit switch 12L is a disconnection detector.

  The drive roller 12A doubles as a delivery roller for drawing out the wire electrode WE from the wire bobbin 11B and delivering it to the processing gap GP, and a tension roller for applying a predetermined tension to the wire electrode WE. The wire electrode WE is wound around the outer periphery of the drive roller 12A by the driven roller 12B and the pinch roller 12C. The drive roller 12A is rotated by the servomotor 12M. The controller controls the rotational speed of the servomotor 12M based on the tension detected by the strain gauge 12T to maintain the tension constant.

  The transport device 13 is means for leading out the used wire electrode WE which has been turned in a substantially horizontal direction by the direction changing pulley 10 to the outside of the processing tank 4. The transport device 13 comprises at least one jet nozzle 13A and an aspirator 13B. The jet nozzle 13A is provided on the tip end side of the lower arm 5 between the direction changing pulley 10 and the take-up roller 14A. The aspirator 13B is provided on the delivery side of the winding roller 14A. There are no obstacles to the wire electrode WE flying in the air on the traveling path (transport path) of the wire electrode WE between the jet nozzle 13A and the aspirator 13B.

  The jet nozzle 13A jets and supplies a high pressure jet toward the aspirator 13B beyond the winding roller 14A. The liquid of the high pressure jet is basically not limited in type, and may be water. Desirably, the fluid of the high pressure jet is the working fluid used for processing so that the high pressure jet does not directly affect the processing by mixing with the processing fluid. The liquid column by the high pressure jet formed in the horizontal direction is connected such that a bridge is bridged between the opening of the jet nozzle 13A and the aspirator 13B.

  The jet nozzle 13A carries the wire electrode WE on the high-pressure jet while guiding the wire electrode WE only by the restraining force of the high-pressure jet in a state where the liquid column of the high-pressure jet is connected with the aspirator 13B. Fly in the direction of 14A. The aspirator 13B sucks and captures the tip of the wire electrode WE sent by the high pressure jet.

  In the present invention, the jet nozzle 13A includes another high-pressure jet generating device capable of squirting and supplying the high-pressure jet with the wire electrode WE restrained in the liquid column and replacing the jet nozzle 13A. Also, even if the aspirator 13B does not have the same structure as that of the aspirator, it is possible to suck the liquid of the high pressure jet and the wire electrode WE together from the front and discharge it backward, and other suctions can be substituted for the aspirator 13B. Includes the device.

  The wire electric discharge machining apparatus according to the embodiment includes a jet nozzle 13C between the lower wire guide and the direction changing pulley 10. In particular, in the wire electric discharge machining apparatus shown in FIG. 1, the jet nozzle 13C passes the lower wire guide to guide the wire electrode WE to the groove-shaped path between the direction changing pulley 10 and the guide block 20, The wire electrode WE helps to advance from the direction changing pulley 10 toward the jet nozzle 13A.

  The recovery device 14 is a means for recovering the used wire electrode WE. Further, the recovery device 14 is a means for causing the wire electrode WE to travel at a constant speed. The recovery device 14 can recover the used wire electrode WE by separating it from the liquid of the high pressure jet. The recovery device 14 includes a winding roller 14A, a winding motor 14M, and a bucket 14R.

  The take-up roller 14A includes a pair of a drive roller rotated by the take-up motor 14M and a driven roller 14B rotated by the drive roller. The winding roller 14A sandwiches the wire electrode WE between a pair of rollers and causes the wire electrode WE to travel at a constant traveling speed. The pair of rollers of the take-up roller 14A can move in the direction separating from each other, release the restraint with respect to the wire electrode WE, and open the traveling path of the wire electrode WE.

  The take-up motor 14M that rotates the drive roller maintains a predetermined rotational speed that is higher than the rotational speed of the servomotor 12M of the tension device 12. Due to the speed difference between the drive roller 12A of the tension device 12 and the take-up roller 14A, the drive roller 12A and the take-up roller are driven to the wire electrode WE while the wire electrode WE travels at a predetermined traveling speed. A tension of a magnitude corresponding to the speed difference with 14A is applied.

  The bucket 14R of the collection device 14 is a collection box for collecting the wire electrode WE. For example, since the bucket 14R is provided with a draining plate 14C such as a wire mesh, the liquid of the high-pressure jet discharged from the aspirator 13B together with the wire electrode WE can be separated and recovered from the wire electrode WE. When it is desired to finely cut and collect the wire electrode WE, the draining plate 14C can be replaced with a fine filter.

  Next, an operation at the time of automatic connection of the wire electric discharge machining apparatus according to the embodiment will be specifically described with reference to FIG. 2 while appropriately referring to FIG. FIG. 2 shows a conveying device of the wire electric discharge machining device shown in FIG. In FIG. 2, the direction of the right hand in the drawing corresponds to the front side of the main machine. FIG. 1 shows the state immediately after the wire electrodes are connected. FIG. 2 shows a state where the wire electrode is flying toward the aspirator in the liquid column by the high pressure jet formed between the jet nozzle and the aspirator.

  Just before the start of the automatic connection, the tip of the wire electrode WE is located at least closer to the processing gap GP than the delivery roller 2A of the automatic connection device 2 shown in FIG. Further, the pair of rollers of the winding roller 14A of the collection device 14 is open, and there is no obstacle in the traveling path of the wire electrode WE between the jet nozzle 13A and the aspirator 13B.

  The control device supplies high-pressure water flow into the guide pipe 2B in a state where the guide pipe 2B of the automatic connection device 2 is disposed at a predetermined height position before starting the automatic connection, and The jet nozzle 13A, the aspirator 13B, and the jet nozzle 13C are operated. When the jet nozzle 13A and the aspirator 13B are activated, a high pressure jet jetted from the jet nozzle 13A to the aspirator 13B is sucked by the aspirator 13B and the liquid column is bridged as if a bridge was formed between the jet nozzle 13A and the aspirator 13B. JA is formed.

  At the start of the automatic wire connection, the control device rotates at a predetermined rotational speed in the delivery direction of the delivery roller 2A of the automatic wire connection device 2. When the tip of the wire electrode WE is inserted into the guide pipe 2B, the control device lowers the guide pipe 2B at the same speed as the moving speed of the wire electrode WE. Since the inside of the guide pipe 2B is filled with high-pressure water flow, the wire electrode WE whose tip is directed downward reaches the upper wire guide unit 3A while being guided by the guide pipe 2B without being caught on the inner wall of the guide pipe 2B. .

  The control device supplies a working fluid jet from the upper wire guide unit 3A to form a liquid column JB by the working fluid jet between the upper and lower wire guides. The tip end of the wire electrode WE moving downward by the delivery roller 2A reaches the lower wire guide unit 3B while being restrained by the liquid column JB.

  The wire electrode WE which has passed through the lower wire guide does not deviate from the traveling path formed in the guide block 20 by the high pressure jet jetted and supplied from the jet nozzle 13 C, and between the direction changing pulley 10 and the guide block 20 The traveling path of the groove shape formed in The direction changing pulley 10, which is an idling roller, guides the wire electrode WE to the jet nozzle 13A in cooperation with the high pressure jet of the jet nozzle 13C.

  When the tip of the wire electrode WE reaches the jet nozzle 13A, the control device increases the rotational speed of the delivery motor 2M to rotate the delivery roller 2A at high speed. The wire electrode WE rides on the liquid column JA of the high-pressure jet formed between the jet nozzle 13A and the aspirator 13B by the jet nozzle 13A and reaches the aspirator 13B at once. The aspirator 13B that has captured the tip of the wire electrode WE sucks the wire electrode WE and sends it in the direction of the bucket 13R.

  The control device stops the jet nozzle 13A and the jet nozzle 13C when the non-illustrated sensor detects that the tip of the wire electrode WE has reached the bucket 14R, and the pair of rollers of the winding roller 13A being open. To close the wire electrode WE. Although the jet nozzle 13A is stopped after completion of the wire connection, the aspirator 13B may be stopped, or may be operated as it is when the diameter of the wire electrode WE is small.

  The wire electric discharge machining apparatus according to the embodiment processes a high pressure jet jetted and supplied from the jet nozzle 13A and a wire electrode WE fed by the high pressure jet at least in the processing tank 4 between the jet nozzle 13A and the aspirator 13B. A cover 7 is provided so as to seal in a sealed manner so as not to contact with the processing fluid stored in the tank 4. In the wire electric discharge machining apparatus according to the embodiment shown in FIG. 2, the cover 7 is closely fixed at one end to the guide block 20 so as to prevent the penetration of machining fluid, and the other end is outside the machining tank 4. It is fixed to the wall of the column 6. Alternatively, the cover 7 can be fixed to the side surface of the lower arm 5, for example.

  The cover 7 makes it possible to put the wire electrode WE on a high pressure jet and fly at a stretch and wire it even if the traveling path of the wire electrode WE is between the jet nozzle 13A and the aspirator 13B in the machining fluid. According to the wire electric discharge machining apparatus of the embodiment having the cover 7, since it is not necessary to discharge the machining fluid from the machining tank 4 every time automatic connection is performed, the time required for the entire operation process of automatic connection is shortened. be able to.

  Even in the case where the workpiece WP is processed without being immersed in the processing fluid, the cover 7 can be provided in order to prevent scattering of the high pressure jet. At this time, since there is no processing fluid on the outside of the cover 7, it is not necessary to seal the cover 7 to make it liquid tight.

  The present invention does not have to be the same as the configuration of the wire electric discharge machining apparatus according to the embodiment described above, and although several examples have already been shown, it does not deviate from the technical concept of the present invention, It is possible to deform, replace members, or combine with other inventions.

  The present invention can be applied to the technical field of electrical discharge machining. The present invention reduces the time required for automatic connection in wire electric discharge machining. The present invention improves the working efficiency in electrical discharge machining and contributes to the development of electrical discharge machining.

DESCRIPTION OF SYMBOLS 1 traveling device 2 automatic wire connection device 2A delivery roller 2B guide pipe 3 wire guide unit 3A upper wire guide unit 3B lower wire guide unit 4 processing tank 5 lower arm 6 column 7 cover 10 direction change pulley 11 supply device 11B wire bobbin 12 delivery device 12A Drive roller 12M Servomotor 13 Transport device 13A Jet nozzle 13B Aspirator 13C Jet nozzle 14 Recovery device 14A Take-up roller 14M Take-up motor 20 Guide block WE Wire electrode WP Workpiece

Claims (2)

  The lower wire includes a lower arm fixed to a machine structure outside the processing tank and provided with a tip located inside the processing tank and supporting a lower wire guide unit guiding the wire electrode at the tip, the lower wire In a wire electric discharge machining apparatus having a direction changing pulley provided immediately below a guide unit and a winding roller provided outside the processing tank, the direction changing pulley and the winding roller are provided at the tip end side of the lower arm. The wire electrode is placed on the high-pressure jet while guiding the wire electrode only by the restraining force of the high-pressure jet so as to discharge the high-pressure jet toward the direction of the winding roller. A jet nozzle for feeding in a direction, and a tip of the wire electrode provided on the outlet side of the winding roller and fed by the high pressure jet Wire electric discharge machining apparatus having a conveying device comprising a aspirator for capturing by suction.   The wire electric discharge machining device according to claim 1, comprising a cover which covers the high-pressure jet and the wire electrode fed by the high-pressure jet at least in the processing tank between the jet nozzle and the aspirator.

Images